Transparent electrode and manufacturing method thereof

Abstract

The invention relates to the technical field of transparent electrodes, in particular to a transparent electrode and a manufacturing method thereof.The manufacturing method comprises the steps that S1, a transparent substrate base material with the visible light transmittance reaching 90% or above is provided, the transparent substrate base material comprises one or more of PET, COP and CPI, and the thickness of the base material ranges from 25 micrometers to 100 micrometers; s2, a conductive metal material is selected as a conductive base material, the conductive metal material comprises one or more of silver and copper, the thickness of a conductive metal layer is not larger than 5 microns, and the purity of the conductive metal layer is larger than 99.99%; s3, performing gridding manufacturing on the conductive base material by using a subtraction etching process to form a relief transparent metal conductive film with the transmittance being greater than 85%; according to the invention, on the transparent substrate base material, low-resistance conductive metal materials such as silver and copper are firstly adopted to manufacture the gridding transparent metal conductive film, and then the ITO conductive layer is combined, so that the resistance is effectively reduced. By means of the design, current transmission is smoother, the electric energy collection and transmission efficiency of the photovoltaic solar cell is greatly improved, and therefore the power generation efficiency is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of transparent electrodes, and specifically to a transparent electrode and a manufacturing method thereof. Background Art

[0002] With the continuous deterioration of the climate environment, efforts are being made across the country and even the world to reduce the use of fossil energy and develop new green energy. Among them, solar energy, wind energy, and hydroelectric power are the main development directions. In the field of photovoltaic solar cells, the conductive electrodes on the battery surface must have advantages such as high transmittance, low resistance, and flat surface to make greater use of solar energy and improve the overall power generation efficiency of photovoltaic solar cells. Traditional transparent electrodes usually use ITO conductive electrodes, but the resistance value of ITO materials is too large. Especially in the case of large sizes, the excessive resistance value greatly affects the power generation efficiency of the battery. In view of this, the present application proposes a new transparent electrode and a manufacturing method thereof, which can reduce the resistance value of traditional ITO conductive electrodes, solve the above problems, and contribute to the iterative upgrade of photovoltaic solar cell products. Summary of the Invention

[0003] The purpose of the present invention is to provide a transparent electrode and a manufacturing method thereof to solve the problems raised in the above background art.

[0004] To achieve the above purpose, the present invention provides the following technical solution: A manufacturing method of a transparent electrode, comprising the following steps:

[0005] S1: Provide a transparent substrate material with a visible light transmittance of more than 90%, the transparent substrate material includes one or more of PET, COP, and CPI, and the substrate thickness is 25um - 100um;

[0006] S2: Select a conductive metal material as the conductive substrate, the conductive metal material includes one or more of silver and copper, the thickness of the conductive metal layer is not greater than 5um, and the purity is greater than 99.99%;

[0007] S3: Use a subtractive etching process to make a grid pattern on the conductive substrate to form a relief transparent metal conductive film with a transmittance greater than 85%;

[0008] S4: Uniformly coat a resin layer on the surface of the relief transparent metal conductive film, the resin layer includes a resin that can be cured by UV irradiation or heating, and the thickness of the resin layer is greater than or equal to the thickness of the conductive metal layer, and the hardness after curing is greater than 2H;

[0009] S5: Cure the resin layer by using UV irradiation or heating;

[0010] S6: Polish the cured resin layer using physical mechanical polishing or chemical polishing processes until the conductive metal layer is exposed, with the surface roughness after polishing being less than 5 nm;

[0011] S7: Deposit an ITO conductive layer on the surface of the transparent metal conductive thin film and the resin layer using magnetron sputtering or vacuum evaporation processes to form a transparent conductive electrode.

[0012] Preferably, in the step of providing the transparent substrate material, when choosing PET as the transparent substrate material, its thickness is 25 microns and the visible light transmittance is 93%.

[0013] Preferably, in the step of selecting the conductive metal material, if silver is used as the conductive substrate, deposit the silver layer by physical vapor deposition, and the thickness of the silver layer is 2 microns.

[0014] Preferably, in the subtractive etching process, when using ferric chloride etching solution to etch the silver conductive substrate, the etching temperature is 30 - 35 °C and the etching time is 10 - 15 minutes.

[0015] Preferably, in the step of coating the resin layer, if a UV - curable acrylic resin is selected, spin - coating method is used for coating, and the rotation speed during coating is 2000 - 3000 revolutions per minute.

[0016] Preferably, in the step of curing the resin layer, when using UV irradiation for curing, the irradiation intensity is 500 - 800 mW / cm 2 , and the irradiation time is 60 - 90 seconds.

[0017] Preferably, in the physical mechanical polishing process, use sandpaper for grinding. First, use sandpaper with a grit size of 800 - 1200 mesh for preliminary grinding, and then use sandpaper with a grit size of 1500 - 2000 mesh for fine grinding.

[0018] Preferably, in the step of depositing the ITO conductive layer, when using magnetron sputtering process, the sputtering power is 150 - 200 W and the sputtering time is 20 - 30 minutes.

[0019] Preferably, in the step of depositing the ITO conductive layer, when using vacuum evaporation process, the evaporation temperature is 400 - 600 °C, the evaporation time is 25 - 35 minutes, the resistance value of the formed transparent conductive electrode is reduced by more than 20% compared with the traditional ITO conductive electrode, the light transmittance reaches more than 85%, and the surface roughness is less than 10 nanometers.

[0020] A transparent electrode is prepared by using the manufacturing method of the transparent electrode.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. The present invention realizes an effective reduction in resistance by first fabricating a grid-shaped transparent metal conductive film on a transparent substrate base material using a low-resistance conductive metal material such as silver or copper, and then combining it with an ITO conductive layer. This design enables smoother current transmission, greatly improving the power collection and transmission efficiency of photovoltaic solar cells, thereby significantly enhancing the power generation efficiency.

[0023] 2. By coating a resin layer on the surface of the grid-shaped transparent metal conductive film and subjecting it to curing and polishing treatments, not only are the unevenness of the metal film effectively filled, but also a very flat substrate is provided for the subsequent coating of the ITO conductive layer. The resulting transparent conductive electrode has a smooth and flat surface, effectively reducing light scattering and increasing the light transmittance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram after the formation of the relief transparent metal conductive film of the present invention.

[0025] Figure 2 It is a schematic structural diagram after the resin layer is coated in the present invention.

[0026] Figure 3 It is a schematic structural diagram after the resin layer is polished in the present invention.

[0027] Figure 4 It is a complete schematic structural diagram of the final transparent conductive electrode of the present invention.

[0028] In the figure: 1. Substrate base material; 2. Conductive base material; 3. Transparent metal conductive film; 4. Resin layer; 5. ITO conductive layer; 6. Transparent conductive electrode. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0030] Please refer to Figures 1 to 4 , the present invention provides a technical solution: a manufacturing method of a transparent electrode, including the following steps:

[0031] S1: Provide a transparent substrate base material 1 with a visible light transmittance of more than 90%, and the transparent substrate base material 1 includes one or more of PET, COP, and CPI, and the substrate thickness is 25um - 100um;

[0032] S2: Select a conductive metal material as the conductive substrate 2. The conductive metal material includes one or more of silver and copper. The thickness of the conductive metal layer is not greater than 5 μm, and the purity is greater than 99.99%;

[0033] S3: Use a subtractive etching process to fabricate a grid pattern on the conductive substrate 2 to form a relief transparent metal conductive film 3 with a transmittance greater than 85%;

[0034] S4: Uniformly coat a resin layer 4 on the surface of the relief transparent metal conductive film 3. The resin layer 4 includes a resin that can be cured by UV irradiation or heating. The thickness of the resin layer 4 is greater than or equal to the thickness of the conductive metal layer, and the hardness after curing is greater than 2H;

[0035] S5: Cure the resin layer 4 by using UV irradiation or heating;

[0036] S6: Polish the cured resin layer 4 by using a physical mechanical polishing or chemical polishing process until the conductive metal layer is exposed. The surface roughness after polishing is less than 5 nm;

[0037] S7: Deposit an ITO conductive layer 5 on the surfaces of the transparent metal conductive film 3 and the resin layer 4 by using a magnetron sputtering or vacuum evaporation process to form a transparent conductive electrode 6.

[0038] In the step of providing the transparent substrate 1, when PET is selected as the transparent substrate 1, its thickness is 25 μm and the visible light transmittance is 93%.

[0039] In the step of selecting the conductive metal material, if silver is used as the conductive substrate 2, the silver layer is deposited by physical vapor deposition, and the thickness of the silver layer is 2 μm.

[0040] In the subtractive etching process, when using ferric chloride etching solution to etch the silver conductive substrate, the etching temperature is 30 - 35 °C and the etching time is 10 - 15 minutes.

[0041] In the step of coating the resin layer, if an acrylic resin that can be cured by UV irradiation is selected, spin coating is used for coating, and the rotation speed during coating is 2000 - 3000 revolutions per minute.

[0042] In the step of curing the resin layer, when using UV irradiation for curing, the irradiation time is 60 - 90 seconds and the irradiation intensity is 500 - 800 mW / cm 2 。

[0043] In the physical mechanical polishing process, sandpaper is used for grinding. First, preliminary grinding is carried out with sandpaper having a particle size of 800 - 1200 mesh, and then fine grinding is carried out with sandpaper having a particle size of 1500 - 2000 mesh.

[0044] In the step of depositing the ITO conductive layer, when using the magnetron sputtering process, the sputtering power is 150 - 200 W, and the sputtering time is 20 - 30 minutes.

[0045] In the step of depositing the ITO conductive layer, when using the vacuum evaporation process, the evaporation temperature is 400 - 600 °C, the evaporation time is 25 - 35 minutes. The resistance value of the formed transparent conductive electrode is reduced by more than 20% compared with the traditional ITO conductive electrode, the light transmittance reaches more than 85%, and the surface roughness is less than 10 nanometers.

[0046] A transparent electrode is prepared by using the manufacturing method of the transparent electrode.

[0047] Select a transparent substrate material 1 with a visible light transmittance of more than 90%. The material can be one or more of PET, COP, and CPI, and the thickness is 25 - 100 μm. Taking PET as an example, after experimental optimization, when the thickness is set to 25 μm, the visible light transmittance is 93%. This parameter takes into account the optical performance, mechanical performance and cost, is conducive to light transmission, can provide support for subsequent processes and reduce costs.

[0048] The conductive substrate 2 is selected from silver, copper, etc. It is required that the thickness of the conductive metal layer does not exceed 5 μm and the purity is greater than 99.99%. When using silver, it is deposited by physical vapor deposition method, and parameters such as vacuum degree and temperature are controlled to obtain a 2 - μm silver layer. This silver layer has good conductivity and can maintain a stable structure in subsequent processes.

[0049] Use the subtractive etching process to make the relief transparent metal conductive film 3, and the transmittance is required to be greater than 85%. When etching the silver conductive substrate, use ferric chloride etching solution, control the temperature at 30 - 35 °C, and the time at 10 - 15 minutes. This condition has been verified by experiments, the etching rate is moderate, and a grid structure with neat lines and meeting the requirements can be accurately made.

[0050] Coat a resin layer 4 on the surface of the relief transparent metal conductive film 3. The resin can be selected from UV - curable or heat - curable types, and the thickness is not less than that of the conductive metal layer. After curing, the hardness is greater than 2H. When selecting the UV - curable acrylic resin, the spin - coating method is used, and the rotation speed is controlled at 2000 - 3000 revolutions per minute to ensure uniform coating and provide a stable basis for subsequent processes.

[0051] Cure the resin layer 4 by UV irradiation or heating. When curing by UV irradiation, the intensity is controlled at 500 - 800 mW / cm 2 , and the time is 60 - 90 seconds. This combination has been verified by experiments, which can fully cure the resin. At the same time, control the wavelength distribution and spot uniformity of the UV light source to ensure consistent curing quality and meet the performance requirements such as wear resistance.

[0052] The resin layer 4 is exposed to the conductive metal layer by physical mechanical or chemical polishing, and the surface roughness is required to be less than 5 nm. During physical mechanical polishing, first rough grind with 800 - 1200 mesh sandpaper to remove large defects, and then fine grind with 1500 - 2000 mesh sandpaper. During grinding, precisely control the pressure, speed and direction to ensure uniform polishing effect and meet the requirements of high flatness.

[0053] An ITO conductive layer 5 is deposited on the surfaces of the transparent metal conductive film 3 and the resin layer 4 to form a transparent conductive electrode 6. During magnetron sputtering, the power is set to 150 - 200 W and the time is 20 - 30 minutes, which can ensure the sputtering rate and film quality, regulate the performance of the ITO conductive layer, and is applicable to scenarios with high requirements for transparent conductivity. During vacuum evaporation, the temperature is controlled at 400 - 600 °C and the time is 25 - 35 minutes, which can form a high-quality ITO conductive layer, reduce the resistance of the transparent conductive electrode by more than 20%, the light transmittance reaches more than 85%, and the surface roughness is less than 10 nanometers, meeting the requirements of high-end optical and electronic devices.

[0054] COP is selected as the transparent substrate base material 1, and its thickness is set to 50 microns. After testing, the visible light transmittance reaches 92%, meeting the optical performance requirements of the present invention for the transparent substrate base material 1, and at the same time this thickness provides stable mechanical support for subsequent processes.

[0055] Copper is determined as the conductive substrate 2, and a copper layer with a thickness of 3 microns is deposited by physical vapor deposition under the condition of strictly controlling parameters such as the vacuum environment and deposition rate. The purity of this copper layer is greater than 99.99%, and it has good conductivity and can adapt to subsequent complex process treatments.

[0056] The copper conductive substrate is etched with ferric chloride etching solution, and the etching temperature is controlled at 32 - 34 °C and the etching time is set to 12 - 14 minutes. Under these conditions, the copper conductive substrate is successfully made into a grid pattern, forming a relief transparent metal conductive film 3 with a transmittance greater than 85%, and the accuracy and quality of the grid lines meet the fine circuit manufacturing standards.

[0057] A heat-curable epoxy resin is selected and coated on the surface of the relief transparent metal conductive film 3 by the doctor blade method. During the coating process, precisely control the doctor blade force and speed to ensure uniform coating of the epoxy resin, forming a resin layer 4 with a thickness greater than or equal to the thickness of the copper conductive layer, and preparing for subsequent curing and other process steps.

[0058] The resin layer 4 is cured by heating, the heating temperature is set to 120 - 130 °C, and the heating time lasts for 30 - 40 minutes. Under this temperature and time condition, the epoxy resin is fully cured, and the hardness of the cured resin layer is greater than 2H, and the curing quality is stable and reliable.

[0059] The cured resin layer 4 is polished using a chemical polishing process. By reasonably adjusting the composition and concentration of the chemical polishing solution and controlling the polishing time within 15 - 20 minutes, the surface roughness after polishing is finally made less than 5 nm, revealing the conductive metal layer and meeting the requirements of the transparent electrode for surface flatness.

[0060] An ITO conductive layer 5 is deposited on the surfaces of the transparent metal conductive thin film 3 and the resin layer 4 using a vacuum evaporation process. The evaporation temperature is controlled at 450 - 550 °C, and the evaporation time is set to 30 - 32 minutes. The ITO conductive layer is successfully deposited to form a transparent conductive electrode 6. After testing, the resistance value of this transparent conductive electrode is reduced by 25% compared to the traditional ITO conductive electrode, the light transmittance reaches 88%, and the surface roughness is less than 8 nanometers.

[0061] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for manufacturing a transparent electrode, characterized in that, It includes the following steps: S1: Provide a transparent substrate material with a visible light transmittance of over 90%, the transparent substrate material includes one or more of PET, COP, and CPI, and the substrate thickness is 25um - 100um; S2: Select a conductive metal material as the conductive substrate, the conductive metal material includes one or more of silver and copper, the thickness of the conductive metal layer is not greater than 5um, and the purity is greater than 99.99%; S3: Use the subtractive etching process to fabricate a grid on the conductive substrate to form a relief transparent metal conductive film with a transmittance greater than 85%; S4: Uniformly coat a resin layer on the surface of the relief transparent metal conductive film, the resin layer includes a resin that can be cured by UV irradiation or heating, and the thickness of the resin layer is greater than or equal to the thickness of the conductive metal layer, and the hardness after curing is greater than 2H; S5: Cure the resin layer by using the method of UV irradiation or heating; S6: Use physical mechanical polishing or chemical polishing process to polish the cured resin layer until the conductive metal layer is exposed, and the surface roughness after polishing is less than 5nm; S7: Deposit an ITO conductive layer on the surface of the transparent metal conductive film and the resin layer by using magnetron sputtering or vacuum evaporation process to form a transparent conductive electrode.

2. The manufacturing method of a transparent electrode according to claim 1, characterized in that: In the step of providing the transparent substrate material, when PET is selected as the transparent substrate material, its thickness is 25 microns and the visible light transmittance is 93%.

3. The manufacturing method of a transparent electrode according to claim 1, characterized in that: In the step of selecting the conductive metal material, if silver is used as the conductive substrate, the silver layer is deposited by physical vapor deposition method, and the thickness of the silver layer is 2 microns.

4. The manufacturing method of a transparent electrode according to claim 1, characterized in that: In the subtractive etching process, when using ferric chloride etching solution to etch the silver conductive substrate, the etching temperature is 30 - 35°C and the etching time is 10 - 15 minutes.

5. The manufacturing method of a transparent electrode according to claim 1, wherein: In the step of coating the resin layer, if an acrylic resin that can be cured by UV irradiation is selected, spin coating method is used for coating, and the rotation speed during coating is 2000 - 3000 revolutions per minute.

6. The manufacturing method of a transparent electrode according to claim 1, characterized in that: In the step of curing the resin layer, when curing by UV irradiation, the irradiation intensity is 500 - 800 mW / cm 2 , and the irradiation time is 60 - 90 seconds.

7. A method for manufacturing a transparent electrode according to claim 1, characterized in that: In the physical mechanical polishing process, sandpaper is used for grinding. First, preliminary grinding is carried out with sandpaper with a particle size of 800 - 1200 mesh, and then fine grinding is carried out with sandpaper with a particle size of 1500 - 2000 mesh.

8. The manufacturing method of a transparent electrode according to claim 1, characterized in that: In the step of depositing the ITO conductive layer, when using magnetron sputtering process, the sputtering power is 150 - 200W and the sputtering time is 20 - 30 minutes.

9. The manufacturing method of a transparent electrode according to claim 1, characterized in that: In the step of depositing the ITO conductive layer, when using vacuum evaporation process, the evaporation temperature is 400 - 600°C, the evaporation time is 25 - 35 minutes, the resistance value of the formed transparent conductive electrode is reduced by more than 20% compared with the traditional ITO conductive electrode, the light transmittance reaches more than 85%, and the surface roughness is less than 10 nanometers.

10. A transparent electrode, characterized in that: Prepared by using the manufacturing method described in claim 1.

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